On 20 Dec 2005 12:50:32 -0800, "z" wrote:

Is the fan before or after the heat exchanger? I.e. is the heat
exchanger under positive or negative pressure?
Thanks,
Pondering

Mine's a big-ass squirrel-cage that forces air TO the
heat-exchanger, presumably also because on the other
side all the parts would have to stand up to more heat.